Depends. No quick and easy ways without some catches/prerequisites.
Do you have extraordinary academic/artistic/business abilities? That might get you EB-1, EB-2 NIW, O-* visa types.
$900k to "invest" at near zero return? That buys you EB-5 green card.
A year of spare time to study and mid 5 figures for tuition and expenses? You could come do masters then stay work for 3 years on STEM OPT. These 3 years should be enough to get a green card to stay permanently, assuming you weren't born in India/China.
Single? Marry an american. It's quick but can get very expensive in the long term though, California is a forced community property state - your spouse essentially owns half of your income.
Chance of winning is under 2% for almost all countries and it's not particularly fast - apply in November, learn in May whether you can immigrate from September.
Regular H1B would be both faster and offer a better chance of winning.
The bar for extraordinary abilities is high. Read up on visa guidelines, consult with some immigration lawyers to see if you stand a chance.
Founding a company doesn't open any extra immigration paths as far as I know. Except for EB-5 - theoretically you could invest those $900k+ into your new company, but there are rules to follow, beware. Your investment needs to create 10 full time jobs for americans and in California in tech you'd likely need way more than $900k for that.
Community property refers to property and assets acquired during the marriage. Italy has almost the exact same concept in marriage/divorce law, called matrimonial property. Community property is split equally if the couple divorces, though many exceptions and possible lawsuits apply, and couples can sign a prenuptial agreement before marrying.
Do you have extraordinary academic/artistic/business abilities? That might get you EB-1, EB-2 NIW, O-* visa types.
$900k to "invest" at near zero return? That buys you EB-5 green card.
A year of spare time to study and mid 5 figures for tuition and expenses? You could come do masters then stay work for 3 years on STEM OPT. These 3 years should be enough to get a green card to stay permanently, assuming you weren't born in India/China.
Single? Marry an american. It's quick but can get very expensive in the long term though, California is a forced community property state - your spouse essentially owns half of your income.